A multistage cuttings
discharge air-screw motor for underground
coal mine drilling comprises a connector, a motor
assembly, a universal shaft
assembly, and a transmission shaft
assembly; the motor assembly inputs
compressed air for rotation driving, the universal shaft assembly and the transmission shaft assembly transmit power, a single-bend outer
pipe of the universal shaft assembly can provide
directional drilling, and the motor assembly is provided with a continuous right-handed spiral groove; when rotating, the screw motor stirs depositing cuttings, assisting air in discharging the cuttings out of a borehole; multistage cuttings
discharge is achieved by adding two sets of reverse bypass holes, and it is ensured that the motor can still normally rotate to
discharge powder when a bit blocks at the bottom of the borehole or cuttings accumulate at the bottom; by providing a one-way valve, high-pressure gas is avoided carrying the cuttings reversely into the motor, causing damage to the motor. The multistage cuttings discharge air-screw motor is used with an underground while-drilling measuring
system in the construction of long boreholes along an underground
coal mine broken-soft coalbed, cuttings discharge effect can be improved, intra-borehole resistance is decreased, construction safety is ensured, and construction depth of boreholes along underground
coal mine broken-soft coalbeds and coalbed drilling catching ratio are increased.